Certain heart arrhythmias, including atrial fibrillation, can cause disability and/or death. The mechanics of the heart can be a factor in the onset and perpetuation of arrhythmias.
Certain ultrasound imaging systems can achieve ultra-high frame rates, e.g., 2000-5000 frames/s, compared with 50-200 frames/s in commercial clinical systems for the depths utilized for transthoracic cardiac applications. Such frame rates can allow for both improved temporal resolution, and motion and deformation mapping. For example, using such techniques, mapping the transient strains occurring in response to the electrical activation, i.e., the electromechanical wave, can be used to map the transmural activation sequence of the normal heart and to locate pacing sites in patients undergoing cardiac resynchronization therapy. Certain of such and related techniques are shown and described, for example and without limitation, in U.S. Patent Application Publication Nos. 2008/0285819 and 2007/0049824, each of which is incorporated by reference herein in its entirety.
However, there is an opportunity for improved systems and techniques for mechanical mapping of cardiac rhythm, including systems and techniques utilizing the spatio-temporal evolution of the local deformations of the heart during e.g., focal tachycardia, flutter, and fibrillation.